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A promising soft magnetic under layer (SUL) structure consisting of anti-parallel coupled soft layers (APS) is investigated to improve the performance of high-density perpendicular recording media. CoCrPt-O recording media with average grain diameter 6 nm, coercivity of 5 kOe and nucleation field of 2 kOe is fabricated on both conventional SUL and APS. Wide-area adjacent track erasure (ATE) is observed for conventional SUL, which increases at lower interlayer spacing ( ). APS structure enables the suppression of ATE even up to = 10 nm. Moreover, APS leads to reduced dc erase noise and improved signal to noise ratio particularly for SUL thicknesses 100 nm.Index Terms-Adjacent track erasure, oxide media, perpendicular recording, recording performance, soft magnetic under layer.

Low temperature deposition of c-axis oriented Sr-ferrite thin films prepared by facing targets sputtering with mixture gas of Ar and Kr

M -type strontium ferrite films were prepared by radio-frequency ͑rf͒ sputtering on fused quartz substrates using different deposition conditions and were subjected to two different types of annealing treatments. The study showed that in addition to the deposition conditions such as rf power, oxygen to argon ratio in the sputtering gas, and target to substrate distance, the postdeposition annealing conditions also play an important role in determining the texture and properties of the films. The films with random orientation or with preferred c-axis orientation either normal to the film plane or in the film plane could be deposited depending on the process parameters chosen. The study carried out by depositing these films on different substrates such as Si͑100͒, Si͑111͒, sapphire͑110͒, and Gd 3 Ga 5 O 12 ͑111͒ showed that though the nature of the substrates plays a role in determining the texture and properties of the films, such effects are less dominant in comparison to the effect of deposition and annealing conditions in the case of strontium ferrite films.

Influence of dynamical dipolar coupling on spin-torque-induced excitations in a magnetic tunnel junction nanopillar J. Appl. Phys. 111, 07C906 (2012) Quasi-omnidirectional electrical spectrometer for studying spin dynamics in magnetic tunnel junctions Rev. Sci. Instrum. 83, 024710 (2012) Thermal-magnetic-electric oscillator based on spin-valve effect J. Appl. Phys. 111, 044315 (2012) Dependence of spin-transfer switching characteristics in magnetic tunnel junctions with synthetic free layers on coupling strength J. Appl. Phys. 111, 07C905 (2012) Electrical manipulation of spin polarization and generation of giant spin current using multi terminal spin injectors J. Appl. Phys. 111, 07C505 (2012) Additional information on J. Appl. Phys. Ferromagnetic resonance (FMR) studies were carried out on Fe/Ni and FeKoNbZr multilayers. A simple model taking into consideration the multilayered nature of the film was used to calculate the field positions and mode intensities of the experimental spectra. The complicated intensity patterns of the modes observed in the FMR spectra of the multilayers were explained in terms of model calculations. The analysis of the spectra showed that the interface in case of these multilayers is not sharp and suggested the formation of interfacial alloy. 0 1995' American Institute of Physics.